The present invention relates to a method and device for inputting a coordinate position. A touch-panel surface is formed by irradiating light on the surface of a white board or a display unit which light is substantially parallel to the surface and a position on the surface of the white board or the display unit is inputted by detecting a position on the surface where the light forming the touch-panel surface is blocked. More particularly the invention relates to a device for inputting coordinate position in which can be detachably attached to the writing surface of a white board or display surface of a display unit. The present invention also relates to a display board system which uses the coordinate-position input device for inputting a manually specified position as the coordinate position.
When a white board (or a blackboard) is used in a meeting or delivering a lecture in a school or a college or the like, in order to record the contents written on the white board it has been general to copy the contents into a notebook by hand or to input the contents in some memory using a word processor or the like. In recent years, in association with the widespread use of digital cameras or the like, there has also been employed a method of recording the contents written on a white board by photographing the contents.
A display board device with a scanner and a printer provided to a white board is becoming popular. In such a device, contents written on the white board are scanned and read, and the read contents can directly be printed (recorded) onto a paper with the help of the printer.
Further, there has been also proposed a display board system having a large display unit such as a plasma display, a coordinate-position input device and a control unit for controlling these components. The coordinate-position input device forms a touch-panel surface on the display surface of the display unit. Information (coordinate position) is input into the coordinate-position input device instead of directly writing on the white board. The information input into the coordinate-position input device is displayed onto the display surface of the display unit and the information can be stored in a storing device such as a memory as well.
As a method of detecting a coordinate position by the coordinate-position input device provided in this type of electronic blackboard device, there is a method of irradiating light onto the entire surface provided in a coordinate position input area and detecting a position of a pen on this surface by detecting the reflected light. Such a method is disclosed in Japanese Patent Laid-Open Publication No. HEI 9-91094. Disclosed in this Japanese Patent Laid-Open Publication No. HEI 9-91094 is a device which scans light so as to irradiate the light onto the entire surface by driving a light source with the help of a driving unit.
There is now a device having a further simplified structure in which the driving unit from the device described above is eliminated. In such a device, the light emitted from a light source is spread in a fan shape with the help of a lens or the like so that the ight is spread over the entire area of the writing surface. FIG. 23 explains the principles of this type of method in a simple maimer. The device shown in the figure has a panel 80 as a writing surface. Reflecting members 2 are provided on three sides of the panel 80. A light source R is provided at a corner in the lower right side thereof in the figure, and a light source L is provided at a corner in the lower left side thereof It should be noted that a point P(xp, yp) on the panel 80 shows a position of a tip of a pen thereon.
In the structure shown in the figure, light beams emitted from the light source R and the light source L are spread by lenses (not shown herein) located in the front section of the light sources R and L respectively, and each of the spread light becomes a flux of light (a fan-shaped light flux) having a fan shape with a central angle of 90 degrees respectively. The fan-shaped light flux is reflected by the reflecting members 2 provided on the three sides of the panel 80, the reflecting members 2 are so designed that the fan-shaped light flux is reflected therefrom along the optical path which is same as at the time of its emission. Therefore, the reflected fan-shaped light fluxes travel in the direction of the light sources r and L along the same optical path as at the time of their emission. Further, for instance, each of the light fluxes is directed towards a light receiving section (not shown herein) by a mirror (not shown herein) provided on the optical path and detected therein.
With such a structure as described above, when the tip of a pen is present at the position of the point P on the panel 80, some light passing through the point P of the fan-shaped light flux is reflected by the pen tip and can not reach the reflecting members 2 (this state is described in the following specification as a state in which the light is blocked by a pen tip). Because of that, only the reflected light of the light passing through the point P of the fan-shaped light flux can not resultantly be detected by the light receiving section. At this point, if a CCD line sensor is used as a light receiving section, for instance, the optical axis of the light not having been received can be identified from the entire reflected light.
It is known that the optical axis of the reflected light is identical to that of the emitted light and that the point P is present on the optical axis of the light which has not been detected, so that the angle of emission of the light passing through the point P can be computed from the optical axis of the reflected light which has not been detected. Accordingly, emission angles xcex8L and xcex8R are obtained from the results of light reception by the two light receiving sections, and optical axis aL and optical axis aR can be obtained from these two emission angles respectively. Further, the coordinates (xp, yp) of the point P can be computed as a point of intersection of those optical axis aL and optical axis aR.
More specifically, the coordinates (xp, yp) of the point P are obtained as described below. Namely,
xpxe2x88x92(Wxc2x7tan xcex8R)/(tan xcex8L+tan xcex8R)xe2x80x83xe2x80x83(1)
                              y          P                =                                            (                              tan                ⁢                                  xe2x80x83                                ⁢                                                      θ                    L                                    ·                  W                  ·                  tan                                ⁢                                  xe2x80x83                                ⁢                                  θ                  R                                            )                        /                          (                                                tan                  ⁢                                      xe2x80x83                                    ⁢                                      θ                    L                                                  +                                  tan                  ⁢                                      xe2x80x83                                    ⁢                                      θ                    R                                                              )                                ⁢                      
                    ⁢                      xe2x80x83                    =                                                    x                p                            ·              tan                        ⁢                          xe2x80x83                        ⁢                          θ              L                                                          (        2        )            
Where W is a distance between the centers of the light source R and light source L.
With the method described above, the coordinate-position input device described above can automatically record the contents written on the panel 80 by reading the locus of a pen tip by means of successively reading the coordinate positions of the pen tip moving along the panel 80.
In the conventional technology, however, there are problems as described below when contents written on a white board is recorded.
In order to record the contents written on a white board, it is required to copy the contents into a notebook by hand or to input the contents with the help of a word processor or the like, so that work by hand is essential in both of the cases. The copying work (copying the contents into a notebook) or the inputting work (inputting the contents into a word processor) is troublesome, inconvenient and therefore disadvantageous.
Secondly, when contents written on a white board are recorded by photographing it with a digital camera or the like, the contents have to be photographed at a location some distance from the board so that the entire white board can be viewed through the viewfinder of the camera. When a photograph is taken from a distance, information written on the white board with the small characters is hard to be interpreted from such a photograph.
On the other hand, the conventional display board device or the conventional display board system has problems as described below.
Although the information on a white board can easily be recorded by scanning the surface of a white board with a scanner and then printing the information onto a paper by using a printer, in this case, the method is realized based on the condition that a display board device with a white board, a scanner, and a printer integrated together is used. With such a configuration, there is a disadvantage that the display board device become very expensive.
Secondly, since the display board device or the display board system is used together with one particular white board or an integrated board with a display unit incorporated in the device or the system, in other words, the display board device or the display board system is not designed for general purpose use. For example, such a system can not be used with a white board or a display unit other than the specific white board or the display unit. Thus, the conventional type of the device or system has not been capable of solving the problems coming up when contents written on a white board or a display unit each generally used as a discrete device are recorded.
Further the conventional type of coordinate-position input device has problems as described below.
When a coordinate-position input device having a touch-panel surface or the like and a display unit which are not previously integrated to each other, the display surface of the display unit is difficult to be used as a touch-panel surface. A coordinate-position input device which can easily be mountable onto the display surface of a display unit has not been proposed.
Secondly, emission angles xcex8R and xcex8L obtained by the method used in the-conventional type of coordinate-position input device depend on the angle (attached angle) at which the light source R and the light source L are attached to the panel 80. Therefore, the coordinates of the point P computed from the emission angles xcex8R and xcex8L also vary in association with the attached angles. If the attached angles are not what they actually should be, then there is a disadvantage that the position of a pen tip can not accurately be read, which results in the fact that the written contents can not accurately be recorded.
A concrete method for computing the emission angles is described below.
FIG. 24 shows a relation between the emission angle xcex8L, the light source L and the attached angle xcex2L of the light source L when the emission angle xcex8L is obtained. It should be noted that while FIG. 24 explains the case for the light source L, the attached angle xcex2R of the light source R can be obtained in a similar manner as described here.
In FIG. 24, an axis as indicated by a phantom line is an optical axis passing through the center of light emitted from the light source L. Herein, a CCD line sensor c as a light receiving section is so provided that the light having the axis as as its optical axis is received by an element positioning at the center o of the sensor. It is assumed that the angle between an axis (described 0-axis in the figure) parallel to the lower edge of the panel 80 and the axis as is the attached angle xcex2L. It is also assumed that a distance between the light source L and the center o of the CCD line sensor c is t, and further a distance between the CCD element which has detected a blockage such as due to a pen tip and the center o thereof is a.
In the example shown in FIG. 24 for obtaining the emission angle xcex8L, at first, an angle as a difference between the attached angle xcex2L and the emission angle xcex8L is xcex1L, and then this angle xcex1L is obtained from the equation described below.
tan xcex1L=a/txe2x80x83xe2x80x83(4)
Then, the emission angle is obtained by the equation described below from the obtained angle xcex1L.
xcex8L=xcex2Lxe2x88x92xcex1Lxe2x80x83xe2x80x83(5)
As described above, it is clear that, when the actual attached angle of the light source L with respect to the CCD line sensor c is displaced from the attached angle xcex2L used in equation (5), the value of xcex8L will be inaccurate and the coordinates (xp, yp) of point P computed according to the value xcex8L will also be inaccurate.
It is required, in order to prevent the location of a blockage from its being sensed inaccurately due to displacement of the attache dangle, that precision of attaching a light receiving section such as a CCD line sensor or a light to the device is mechanically enhanced or that adjustment precision after attachment thereof is enhanced. However, much of the technology described above requires guesswork and experience of skilled engineers, and because of that, it has been thought to be generally inappropriate that this technology is applied to products mass-produced.
It is a first object of the present invention to enable, for the purpose of solving the problems described above, recording of contents written on a white board easily and readably without using the hands as well as to provide general versatility applicable to an ordinary white board.
It is a second object of the present invention to provide a coordinate-position input device usable by easily mounting on a display surface of a display unit with high general versatility.
It is a third object of the present invention to provide a coordinate-position input device attachable with higher precision as compared to a light receiving section and a light source as well as to provide a display board system using this coordinate-position input device.
Further, it is a fourth object of the present invention to provide a coordinate-position input device which can accurately compute displacement of an attached angle and accurately read written contents by easily correcting this displacement as well as to provide a display board system using this coordinate-position input device.
With the present invention, a frame body having two optical units integrated in it is detachably attached to a writing surface of a white board or a display surface of a display unit by utilizing mounting members. Further, a touch-panel surface is formed on the writing surface or the display surface by using the two optical units as well as reflecting members located in the frame body and a position where the light that forms the touch-panel surface is blocked is detected. Thus it becomes possible to input a coordinate position on the writing surface or the display surface.
With the present invention, it is possible to input a coordinate position, by detachably attaching a frame body to a writing surface of a white board or a display surface of a display unit using mounting members, further attaching two optical units to the frame body to adjust each irradiating direction of light therefrom, forming a touch-panel surface with the two optical units as well as reflecting members located in the frame body and detecting a position where the light for forming the touch-panel surface is blocked, on the write-in surface or the display surface thereof.
With the present invention, a computing section computes a coordinate position of a blocked point on the writing surface or the display surface from a direction of reflected light not received by light receiving sections of the two optical units as well as from a distance between the light receiving sections thereof, so that a coordinate position of the blocked point can be outputted from the coordinate-position input device.
With the present invention, when a coordinate-position input mode and an input suspend mode are exclusively specified by a specifying unit, a control unit provides controls over the two optical units and/or the computing section according to the specified mode, which allows the user to freely select either the case where a coordinate position is inputted through the touch-panel surface or the case where a coordinate position is not inputted.
With the present invention, the frame body can be attached in any of the longitudinal direction and the lateral direction, which allows flexibility for attaching the frame body to a writing surface of a white board or a display surface of a display unit to be enhanced.
With the present invention, a mounting member is made with any of a magnet, a hook, a form enabling hanging, a suction cup, a face-type fastener, an engaging form, and an adhesive or a combination thereof, which allows the device of the invention to be attached to the white board or display unit with its simple structure.
With the present invention, each edge of the frame is extendable in multi-steps by an adjustment mechanism, and the reflecting member is wound into a roll inside the adjustment mechanism when the frame is contracted, so that the frame body may be contracted when it is to be carried or extended when it is to be used, which allows its transportability to be enhanced.
With the present invention, each edge of the frame is extendable in multi-steps by an adjustment mechanism, and the reflecting member is also extendable in multi-steps together with the frame edge, so that the frame body may be contracted when it is to be carried or extended when it is to be used, which allows its transportability to be enhanced.
With the present invention, the coordinate position of obstacle can be stored in a storing section.
With the present invention, the coordinate position of the obstacle can be stored in an external memory, and the stored contents can easily be accessed by utilizing some other equipment by attaching the external memory thereto.
With the present invention, the coordinate position of the obstacle can be stored on a frame memory.
With the present invention, even when a light emitting unit and a light detecting unit are attached to or detached from an area defining member, a positional relation between the light emitting unit and the light detecting unit can be maintained to be constant at any time.
With the present invention, even when a light emitting unit and a light detecting unit are attached to or detached from an area defining member, a positional relation between the light emitting unit and the light detecting unit can be maintained to be constant at any time, and in addition the state of emission and detection can also be maintained to be constant at any time.
With the present invention, the precision of alignment between an optical unit and an area defining member can comparatively easily be enhanced.
With the present invention, it is possible to instantly and quantitatively recognize the displacement in an angle at which the optical unit is attached.
With the present invention, it is possible to instantly and quantitatively recognize the displacement in an angle at which the optical unit is attached and detect the coordinates of the position of a blockage corresponding to this displacement.
With the present invention, it is possible to visually recognize the occurrence of displacement in an angle at which the optical unit is attached and detect the coordinates of the position of a blockage corresponding to this displacement.
With the present invention, the configuration thereof can be simplified by suppressing an increase in the number of components.
With the present invention, any one of the coordinate-position input devices described above can be applied to a display board system.
Other objects and features of this invention will become understood from the following description with reference to the accompanying drawings.